Hopefully someone can help me with this problem. When I scroll in
Excel using the mouse wheel it usually scrolls the sheet in the
up/down direction. However, occasionally the scroll function changes
suddenly and scrolls in the left/right direction. I don't know how it
happens and I don't know how to fix it. It seems to happen randomly
and it happens in all types of sheets, large or small. Once it is in
left/right mode I do not seem to be able to get it back in up/down
mode. I tried to 'force' the scroll function back into up/down mode by
scrolling/clicking on the vertical scroll bar, but to no avail. The
only 'solution' I found is to restart Excel.
If anyone is experiencing similar problems or if anyone knows the
solution to this problem please let me know because it's driving me
mad.

Thanks,
Chris

By the way, I use Excel XP (2003)